scholarly journals Behaviour of tire shred – sand mixtures

2004 ◽  
Vol 41 (2) ◽  
pp. 227-241 ◽  
Author(s):  
Jorge G Zornberg ◽  
Alexandre R Cabral ◽  
Chardphoom Viratjandr
Keyword(s):  
Shear Strength ◽  
Aspect Ratio ◽  
Large Scale ◽  
Experimental Testing ◽  
Volumetric Strain ◽  
Confining Pressure ◽  
Stress Strain ◽  
Aspect Ratios ◽  
Strain Behaviour ◽  
Tire Shreds

Tire shreds and tire shred – soil mixtures can be used as alternative backfill material in many geotechnical applications. The reuse of tire shreds may not only address growing environmental and economic concerns, but also help solve geotechnical problems associated with low soil shear strength. In this study, an experimental testing program was undertaken using a large-scale triaxial apparatus with the goal of evaluating the optimum dosage and aspect ratio of tire shreds within granular fills. The effects on shear strength of varying confining pressure and sand matrix relative density were also evaluated. The tire shred content and tire shred aspect ratio were found to influence the stress–strain and volumetric strain behaviour of the mixture. The axial strain at failure was found to increase with increasing tire shred content. Except for specimens of pure tire shreds and with comparatively high tire shred content, the test results showed a dilatant behaviour and a well-defined peak shear strength. The optimum tire shred content (i.e., the one leading to the maximum shear strength) was approximately 35%. For a given tire shred content, increasing the tire shred aspect ratio led to increasing overall shear strength, at least for the range of tire shred aspect ratios considered in this study. The shear strength improvement induced by tire shred inclusions was found to be sensitive to the applied confining pressure, with larger shear strength gains obtained under comparatively low confinement.Key words: tire shreds, shear strength, reinforcement, triaxial testing, stress–strain behaviour.

scholarly journals Reuse of “End Of Life Tyres” Tyre Chips – Sand Mixture Mechanical Study

2012 ◽  
Vol 58 (3) ◽  
pp. 379-406
Author(s):  
E. Dembicki ◽  
M. Kowalczyk ◽  
P. Gotteland
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Experimental Testing ◽  
Volumetric Strain ◽  
Confining Pressure ◽  
Sand Mixture ◽  
Triaxial Apparatus ◽  
Strain Behaviour ◽  
Mechanical Study ◽  
End Use

Abstract The use of shredded tyre in civil engineering applications is a significant potential end use market. The reuse of tyre chips may not only address growing environmental and economic concerns, but also help to solve geotechnical problems associated with low shear strength. The purpose of this paper is to investigate the properties of tyre chips and tyre chips - sand mixture, and to find the mixture with the highest shear strength. In this study, an experimental testing program was undertaken using a large - scale triaxial apparatus with the goal of evaluating the optimum percentage of tyre chips in sand. The effects on shear strength of varying percentage of tyre chips and varying confining pressure were studied. Tyre chips content was suspected to have influence on stress - strain and volumetric strain behaviour of the mixture. Some tests were conducted to check the influence of number of used membranes, of saturation and compaction, on sample properties.

scholarly journals Effect of Rock Particle Content on the Mechanical Behavior of a Soil-Rock Mixture (SRM) via Large-Scale Direct Shear Test

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Longqi Liu ◽  
Xuesong Mao ◽  
Yajun Xiao ◽  
Qian Wu ◽  
Ke Tang ◽  
...  
Keyword(s):  
Shear Strength ◽  
Normal Stress ◽  
Large Scale ◽  
Direct Shear Test ◽  
Shear Test ◽  
Volumetric Strain ◽  
Direct Shear ◽  
Stress Strain ◽  
Particle Content ◽  
Rock Particle

The mechanical strength of the landslide deposits directly affects the safety and operation of the roads in the western mountainous area of China. Therefore, the research is aimed at studying the mechanisms of a landslide deposit sample with different rock particle contents by analyzing its characteristics of the stress-strain behavior, the “jumping” phenomenon, the volumetric strain, and the shear strength parameters via a large-scale direct shear test. Stress-strain results show that stress-strain curves can be divided into 3 different stages: liner elastic stage, yielding stage, and strain-hardening stage. The shear strength of SRM behaves more like “soil” at a lower rock particle content and behaves more like “rock joints” at a higher rock particle content. Characteristics of the “jumping” phenomenon results show that the “intense jumping” stage becomes obvious with the increasing rock particle content and the normal stress. However, the lower the rock particle content is, the more obvious the “jumping” phenomenon under the same normal stress is. Volumetric strain results show that the sample with a lower rock particle content showed a dilatancy behavior under the low normal stress and shrinkage behavior under the high normal stress. The dilatancy value becomes smaller with the increasing normal stress. The maximum shear stress value of the rock particle content corresponds to the maximum value of dilatancy or shrinkage. We also conclude that the intercept of the Mohr failure envelope of the soil-rock mixture should be called the “equivalent cohesion,” not simply called the “cohesion.” The higher the normal stress and rock particle content are, the bigger the equivalent cohesion and the internal friction angle is.

scholarly journals Characterisation of Geogrid and Waste Tyres as Reinforcement Materials in Railway Track Beds

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4162
Author(s):  
Lihua Li ◽  
Yanan Fang ◽  
Bowen Cheng ◽  
Na Chen ◽  
Mi Tian ◽  
...  
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Confining Pressure ◽  
Railway Track ◽  
Strength Ratio ◽  
Stress Strain ◽  
Geogrid Reinforcement ◽  
Deviator Stress ◽  
Waste Tyres ◽  
Waste Tyre

The engineering behaviour of ballast is an important factor to determine the stability and safety of railway tracks. This paper examines the stress–strain, shear strength, peak deflection stress and reinforcement strength ratio of different reinforcement materials and reinforcement locations in ballast track bed layers based on large scale static triaxial shear tests. The results show that geogrid and waste tyre reinforcement have a significant effect on the peak deviator stress of railway track bed layers and the stress–strain relationship is strain-hardened. The peak deviator stress and shear strength of geogrid reinforcement are greater under the same conditions compared with waste tyres. The reinforcement of geogrid and waste tires increases the shear strength of the track bed significantly. The more layers of geogrid reinforcement, the more energy is required for the deformation of the track bed. The energy required for deformation is greater in the centre of the waste tyre than in the other reinforced forms, and the energy required for deformation is minimal in the fully reinforced form. Excessive tyre reinforcement changes the stiffness of the track bed layer, leading to an increase in the settlement rate. The reinforcement strength ratio between geogrid and waste tyre increases significantly with the increasing of the confining pressure and reinforcement layers. Moreover, the reinforcement strength ratio of the geogrid is significantly higher than that of the waste tyre.

scholarly journals High resolution parameter study of the vertical shear instability

2020 ◽  
Vol 499 (2) ◽  
pp. 1841-1853
Author(s):  
Natascha Manger ◽  
Hubert Klahr ◽  
Wilhelm Kley ◽  
Mario Flock
Keyword(s):  
Aspect Ratio ◽  
Large Scale ◽  
Dead Zone ◽  
Pressure Ratio ◽  
Theoretical Models ◽  
Shear Instability ◽  
Vertical Shear ◽  
Parameter Study ◽  
Aspect Ratios ◽  
Strong Scaling

ABSTRACT Theoretical models of protoplanetary discs have shown the vertical shear instability (VSI) to be a prime candidate to explain turbulence in the dead zone of the disc. However, simulations of the VSI have yet to show consistent levels of key disc turbulence parameters like the stress-to-pressure ratio α. We aim to reconcile these different values by performing a parameter study on the VSI with focus on the disc density gradient p and aspect ratio h = H/R. We use full 2π 3D simulations of the disc for chosen set of both parameters. All simulations are evolved for 1000 reference orbits, at a resolution of 18 cells per h. We find that the saturated stress-to-pressure ratio in our simulations is dependent on the disc aspect ratio with a strong scaling of α∝h2.6, in contrast to the traditional α model, where viscosity scales as ν∝αh2 with a constant α. We also observe consistent formation of large scale vortices across all investigated parameters. The vortices show uniformly aspect ratios of χ ≈ 10 and radial widths of approximately 1.5H. With our findings we can reconcile the different values reported for the stress-to-pressure ratio from both isothermal and full radiation hydrodynamics models, and show long-term evolution effects of the VSI that could aide in the formation of planetesimals.

Post-Peak Behaviour of Sensitive Clays in Undrained Shear

1968 ◽  
Vol 5 (2) ◽  
pp. 59-68 ◽  
Author(s):  
B Ladanyi ◽  
J P Morin ◽  
C Pelchat
Keyword(s):  
Shear Strength ◽  
Indirect Method ◽  
Peak Stress ◽  
Large Strains ◽  
Peak Strain ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Structural Breakdown ◽  
Undrained Shear

The post-peak stress-strain behaviour in undrained shear of three different clays has been investigated by using an indirect method. This method, which is in principle similar to that used by Kallstenius (1963), consists in first compressing a clay specimen to a given post-peak strain between two parallel platens and subsequently determining its current remoulded strength by the laboratory vane method. By a repeated compression procedure, axial strains of up to 200 per cent have been attained. As the three clays tested differed widely in sensitivity, a comparison of their post-peak behaviour made clearly apparent the effect of structural breakdown on the reserve shear strength at large strains.

The Effect of Aspect-Ratio on the Development of the Large-Scale Structures in the Three-Dimensional Wall Jet

2005 ◽  
Author(s):  
Joseph W. Hall ◽  
Daniel Ewing
Keyword(s):  
Aspect Ratio ◽  
Large Scale ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Decomposition Analysis ◽  
Wall Pressure ◽  
Symmetric Mode ◽  
Large Scale Structures ◽  
Aspect Ratios ◽  
Scale Structures

The development of the large-scale structures in three-dimensional wall jets exiting rectangular nozzles with aspect-ratios of 1 and 4 was investigated using simultaneous measurements of the fluctuating wall pressure across the jet. The pressure fluctuations in the jets were asymmetric and caused the fluctuating wall pressure to be poorly correlated across the jet centerline. A Proper Orthogonal Decomposition analysis indicated that both the first and second modes make similar contributions to the variance of the fluctuating pressure, and were symmetric and antisymmetric, respectively, and the interplay between these modes caused the asymmetry in the instantaneous pressure fluctuations across the jet centreline. A wavelet analysis of the instantaneously reconstructed pressure fields indicated that the fluctuations were predominantly in two frequency bands near the jet centerline, but were only contained in one band on the outer lateral edges of the jet, indicating there were two different large-scale motions present. The development of large-scale structures in the two jets initially differed in the intermediate field with the antisymmetric mode being more prominent in the square jet and the symmetric mode being more prominent in the larger aspect-ratio jet. Further downstream, the symmetric mode was more prominent in both jets.

scholarly journals Shear Strength and Pull-Out Response of Tire Shred-Sand Mixture Reinforced with Deformed Steel Bars

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Beenish Jehan Khan ◽  
Irshad Ahmad ◽  
Hassan Nasir ◽  
Abdullah Abdullah ◽  
Qazi Khawar Gohar
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Friction Angle ◽  
Sand Mixture ◽  
Strain Behavior ◽  
Backfill Material ◽  
Pull Out ◽  
Tire Shreds ◽  
Steel Bars ◽  
Different Diameters

The use of scrap tires in various engineering applications has been extensively explored. The present study has the following aim: to evaluate the suitability of tire-sand mixtures as backfill material based on its shear strength. To achieve this objective, modified Proctor compaction tests were performed on tire shred-sand mixture with mixing proportions by weight of tire shreds and sand (0/100, 20/80, 30/70, and 40/60) using different sizes of tire shreds (50 mm, 75 mm, and 100 mm). Based on the results of the modified Proctor compaction test, the two mixing proportions, i.e., tire shred/sand, 20/80 and 30/70, respectively, were selected. Large-scale direct shear test indicated higher internal friction angle and cohesion values for tire shred-sand mixtures (30/70) with 100 mm tire size (38.5° and 19 kPa) as compared with sand-only backfill material (30.9° and 0 kPa). Based on stress-strain behavior plots, it was indicated that the inclusion of tire shreds imparts ductility to backfill mixtures. To achieve the second objective, the pull-out tests were performed with deformed steel bars of two different diameters (12.7 mm and 15.8 mm) embedded in various backfill mixtures prepared with tire shreds of three different sizes (50, 75, and 100 mm). The pull-out test result indicated that the deformed steel bars exhibit higher pull-out resistance in tire shred-sand mixtures (9.9 kN/m) compared with sand-only backfill material (4.1 kN/m).

Study on Influence of Geotechnical Grille Characteristic on Mechanics Properties of Reinforced Sand-Gravel

2011 ◽  
Vol 243-249 ◽  
pp. 2176-2182
Author(s):  
Bin Xu ◽  
De Gao Zou ◽  
Tao Gong ◽  
Xian Jing Kong ◽  
Jing Bi
Keyword(s):  
Shear Strength ◽  
Residual Strength ◽  
Large Scale ◽  
Great Influence ◽  
Volumetric Strain ◽  
Peak Strength ◽  
Brittleness Index ◽  
Triaxial Tests ◽  
Reinforced Sand ◽  
Initial Modulus

A series of large scale consolidated drained shear triaxial tests were performed on geotechnical grille reinforced sand-gravel specimens, the aim was to study influence of elongation and strength characteristic of geotechnical grille on initial modulus, peak strength, residual strength, brittleness index, volumetric strain and shear strength of reinforced sand-gravel. The results show that: the elongation of geotechnical grille used in the sand-gravel specimens has great influence on residual strength, brittleness index and cohesion of reinforced sand-gravel, but the initial modulus, peak strength and volumetric strain are affected slightly.

Some geotechnical characteristics of fragmented Queenston Shale

1985 ◽  
Vol 22 (3) ◽  
pp. 403-408 ◽  
Author(s):  
R. H. Caswell ◽  
B. Trak
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Shear Strength ◽  
Granular Material ◽  
Key Words ◽  
Strength Properties ◽  
Stress Strain ◽  
Triaxial Apparatus ◽  
Geotechnical Characteristics ◽  
Strain Behaviour

This paper presents the results of an experimental study to determine the stress–strain behaviour of fragmented Queenston Shale from Russell, Ontario and to investigate how its strength properties altered when the material was subjected to repeated slaking cycles. Slaking tests showed that large (cobble-size) blocks of the material degrade rapidly to a particle size of 20 mm upon exposure to water and air. Consolidated drained tests in a large triaxial apparatus under monotonic loading conditions on specimens of fresh and slaked material were performed. They indicate that the shear strength of fragmented Queenston Shale of particle size smaller than 20 mm is not affected by slaking. Key words: Queenston Shale, compaction shale, granular material, rockfill, slaking, shear strength, consolidated drained tests.

Shear strength and stress—strain behaviour of Athabasca oil sand at elevated temperatures and pressures

1987 ◽  
Vol 24 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. G. Agar ◽  
N. R. Morgenstern ◽  
J. D. Scott
Keyword(s):  
Shear Strength ◽  
Oil Sands ◽  
Elevated Temperatures ◽  
Triaxial Compression ◽  
Substantial Reduction ◽  
Hyperbolic Model ◽  
Oil Sand ◽  
Hydrocarbon Gases ◽  
Stress Strain ◽  
Strain Behaviour

The results of a series of triaxial compression tests on undisturbed samples of Athabasca oil sand at elevated temperatures ranging from 20 to 200 °C are summarized. The material tested had experienced gradual unloading and depressurization as a result of erosion in the Saline Creek valley near Fort McMurray. More deeply buried oil sands are known to contain much higher concentrations of dissolved hydrocarbon gases in the pore fluids. The measured shear strength of Athabasca oil sand did not change significantly as a result of the increased temperatures that were applied. The strength of Athabasca oil sand (at 20–200 °C) was found to be greater than comparable shear strengths reported for dense Ottawa sand (at 20 °C). Although heating to 200 °C had little effect on shear strength, it is recognized that pore pressure generation during undrained heating may cause substantial reduction of the available shearing resistance, particularly in gas-rich oil sands. The experimental data were used to investigate the influence of such factors as stress path dependency, microfabric disturbance, and heating to elevated temperatures on the shear strength and stress–strain behaviour of oil sand. Curve fitting of the test data suggests that the hyperbolic model is a useful empirical technique for stress—deformation analyses in oil sands. Hyperbolic stress—strain parameters derived from the experimental results for Athabasca oil sand are presented. Key words: oil sand, Athabasca oil sand, tar sand, shear strength, stress, strain, deformation, heating, high temperature, elevated temperatures, high pressure, elevated pressure, thermal properties, drained heating, undrained heating, triaxial compression testing.

Sign in / Sign up

Export Citation Format

Share Document